ABSTRACT
Rubus lambertianus Ser. var. paykouangensis (Levl.) Hand.-Mazz. is great important in the phylogeny and evolution of the genus Rubus L. in the family Rosaceae. The chloroplast genome of R. lambertianus var. paykouangensis reported in this study is 156177 bp in length, and it has an average GC content of 37.18%. The complete chloroplast genome showed a typical quadripartite structure, comprising a small single copy (SSC) region (18,730 bp) and a large single copy (LSC) region (85,883 bp), both of which were separated by a pair of inverted repeats (IRs, 25,782 bp). This plastome was discovered to contain 129 different genes (112 unique), including 85 protein-coding genes (79 unique), 36 tRNA genes (29 unique), and 8 rRNA genes (4 unique). The published chloroplast genome of R. lambertianus var. paykouangensis will provide a significant insight into elucidating the phylogenetic relationship of taxa within the genus Rubus of the family Rosaceae.
ABSTRACT
Three luminescent polymorphs based on a new copper(I) complex Cu(2-QBO)(PPh3)PF6 (1, PPh3 = triphenylphosphine, 2-QBO = 2-(2'-quinolyl)benzoxazole) have been synthesized and characterized by FT-IR, UV-vis, elemental analyses, and single-crystal X-ray diffraction analyses. Each polymorph can reversibly convert from one to another through appropriate procedures. Interestingly, such interconversion can be distinguished by their intrinsic crystal morphologies and colors (namely α, dark yellow plate, ß, orange block, γ, light yellow needle) as well as photoluminescent (PL) properties. X-ray crystal structure analyses of these three polymorphs show three different supramolecular structures from 1D to 3D, which are expected to be responsible for the formation of three different crystal morphologies such as needle, plate, and block. Combination of the experimental data with DFT calculations on these three polymorphs reveals that the polymorphic interconversion is triggered by the conformation isomerization of the 2-QBO ligand and can be successfully controlled by the polarity of the process solvents (affecting the molecular dipole moment) and thermodynamics (affecting the molecular total energy). It is also found that the different crystal colors of polymorphs and their PL properties are derived from different θ values (dihedral angle between benzoxazolyl and quinolyl group of the 2-QBO ligand) and P-Cu-P angles based on TD-DFT calculations. Moreover, an interesting phase interconversion between γ and ß has also been found under different temperature, and this result is consistent with the DFT calculations in which the total energy of ß is larger than that of γ. This polymorphism provides a good model to study the relationship between the structure and the physical properties in luminescent copper(I) complexes as well as some profound insights into their PL properties.
ABSTRACT
In the title heteroleptic cuprous complex, (acetonitrile-κN)({2-[2-(diphenylphosphanyl)phenoxy]phenyl}diphenylphosphane-κ(2)P,P')[2-(pyridin-4-yl-κN)-1,3-benzoxazole]copper(I) hexafluoridophosphate, [Cu(C(36)H(28)OP(2))(CH(3)CN)(C(12)H(8)N(2)O)]PF6, conventionally abbreviated [Cu(POP)(CH3CN)(4-PBO)]PF6, where POP is the diphosphane ligand {2-[2-(diphenylphosphanyl)phenoxy]phenyl}diphenylphosphane and 4-PBO is the N-containing ligand 2-(pyridin-4-yl)-1,3-benzoxazole, the asymmetric unit consists of a hexafluoridophosphate anion and a whole mononuclear cation, where the Cu(I) centre is coordinated by two P atoms from the POP ligand, by one N atom from the 4-PBO ligand and by the N atom of the coordinated acetonitrile molecule, giving rise to a CuP2N2 distorted tetrahedral coordination geometry. The electronic absorption, photoluminescence and thermal stability properties of this complex have been studied on as-synthesized samples, which had previously been examined by powder X-ray diffraction. A yellow emission signal is attributed to an excited state arising from metal-to-ligand charge transfer (MLCT).
